Integrated Constitutive Model for Flow Behavior of Pure Titanium Considering Interstitial Solute Concentration

Abstract

The aim of this work is to develop a constitutive model that can predict the flow behavior of pure Ti with different interstitial concentrations and grain sizes. To build a database required for identifying material constants, three different grades of Ti were subjected to tensile tests at temperatures of 223, 300, 473, 673 or 773 K and at a fixed strain rate of 10(-3)s(-1). In the modeling procedure, the mechanical threshold stress model was further modified to capture both the hardening effects attributed to the changes in equivalent oxygen concentration (O-eq) and the softening effect caused by deformation heating at high strain rates. The developed model can reasonably predict the flow behavior of pure Ti having different O-eq (0.14-0.32 wt%), and grain size (14.5-90 mu m) over a temperature range of 135 to 673 K, and a strain rate range of 2x10(-4) to 1400 s(-1)